The present invention is directed to a device designed to handle and orient flat workpieces which are arranged in batches, and specifically to arrange flat workpieces consisting of box blanks or corrugated box blanks.
In the processing industry for box blanks or corrugated box blanks, it is frequently necessary to have to carry batches of the box blanks or of folded box blanks from one point of a production line to another; for example, to carry a batch of flat workpieces from one unit of the production machine to another. In order to effect this carrying operation, motorized conveyors, for example belts or rollers, are generally used. It may also be necessary to orient the batch to be carried so as to have the batch directed in a predetermined position toward an inlet of the next processing unit. To this aim, the use of swivelling or rotating tables equipped with carrier balls have been suggested.
U.S. Pat. No. 5,000,305, whose disclosure in incorporated herein by reference thereto and which claims priority from the same French Application as French Patent Reference 2,637,878, is related to such a rotating table. In this patent, the batches of flat workpieces are handled and oriented by means of a device having a carrier plane surface equipped with balls. A central disk is also provided with balls and is arranged within the carrier plane surface and is able to effect, upon request, a vertical movement which enables the charge of blanks supported by the disk to be rotated when the disk is in an upper position above the plane of the table. The charge, i.e., the batch of flat workpieces, will be angularly turned either by 90.degree. or by 180.degree. and then the central disk will come back to its lower position and the batch will then be carried in a linear way into the production line.
The balls of the carrier plane surface, as well as the balls of the central disk, will be driven by means of two endless belts whose upper ends travel on supporting elements and are in contact with the balls of the carrier plane surface, as well as with the balls of the central disk when the latter is in its lower position. With such a device, it is also possible to control both the linear motion of the endless belt and the rotation of the central disk when the latter is in its lower position in order to obtain an angular or orthogonal orientation of the batch being carried.
A man skilled in the art is also aware of devices in which the batches of flat workpieces are shifted sidewise to the left-hand side or the right-hand side as well as being angularly oriented. In those devices, the sidewise shift is ensured by a rectangular ball plate moving crosswise to the travelling direction of the ball driving appliances, which are arranged directly underneath the plate.
The angular orientation of the batches of the flat workpiece is obtained by means of the ball driving appliance consisting of four sections motorized individually. This arrangement allows changing the speed and the drive direction of every motorized section and, thereby, allows also an orthogonal and angular orientation of the batches of the flat workpiece.
The main drawback of this kind of device remains in the fact that the orientation of the batch carried is not exactly ensured and implies an important investment in electronic control components which, hence, increases the cost of the device. Moreover, in the first device described hereinbefore, if the operation of the orientating of the batch is to be effected when the central disk is in the lower position, it will be difficult or even impossible to orient a batch whose dimensions are larger than the diameter of the central disk.
As a rule in practical use, the two above-mentioned devices are combined in order to reduce the cost and complexity of the electronic control components. However, this combination enhances the encumbrance of this section of the production line and results in a considerable loss of space in a board or blank processing factory.